Relay protection reacted because of the short circuit in the switchyard. As a result, a 330 kW power line was switched off. The first unit reactor was scrammed and switched of the electric network.

The background radiation at the Leningrad Nuclear Power Plant (LNPP) site and neighbouring areas was reported to be within preset limits and did not exceed natural levels, the LNPP’s press service reported.

“Specialists are now investigating the reasons and to find out what repairs are necessary,” Sergey Averyanov, chief of LNPP press-service, told Bellona Web.

According to Averyanov, the repairs may take about two days, though the units themselves do not need to be repaired.

At the same time, according to experts, any emergency shut down has a negative impact on the state of the units.

“Every emergency shut down influences the functioning of the whole unit. While operating in an abnormal mode, the reactor core undergoes an excessive load. As a result, a release of radioactivity is possible,” said Alexander Nikitin, chairman of Bellona St.Petersbnurg.

According to Nikitin, an emergency shut down contributes to amortisation of all the systems and mechanisms as they are work at maximum exploitation regeme. “Taking into account that the reactor is old and its lifetime is already extended there are some concerns about its safety,” Nikitin added.

“The last incident of such kind happened at LNPP on December 15,” said Averyanov. Ihe said that in general emergency shut downs happen two or three times a year at the LNPP.

The possibility of new incidents

“Inasmuch as the LNPP units have run out of their lifetime we expect that such incidents can be repeated in the future,” said Oleg Bodrov, chairman of the Green World NGO in Sosnovy Bor, in an interview with Bellona Web.

The aging nuclear plants in the Northwest Russian region cause danger for all the Baltic countries, Bodrov said. Environmentalists fear that such incidents will become more and more commonplace.

“The LNPP is not the only nuclear plant on the shores of the Baltic Sea. Just recently, on July 25, a more serious accident happened as a result of a short circuit at one of the units of the Sweedish Forsmark plant,” Bodrov said. After the electricity failure, two of four backup diesel generators failed to start automatically and the reactor was out of control for 20 minutes, Swediah authorities reported.

“It was sheer luck that [the blackout] didn’t lead to a catastrophe worse than Chernobyl,” former Forsmark head Lars-Olov Hoeglund told Swedish journalists.

“This time we were lucky – all the systems functioned well. On the other hand, the incident shows that such cases can not be excluded. The water exchange in the Baltic Sea is very poor and any accident will be a catastrophe for the people of the region,” Bodrov said.

In Bodrov’s opinion, it is necessary to create a transnational radioactive safety strategy for the Baltic region.